1. Field of the Invention
The present invention relates to a liquid transport head which makes it possible to control the flow of a liquid in a flow passage, and a liquid transport apparatus provided with the same.
2. Description of the Related Art
An ink-jet head, which discharges an ink to form an image on the recording paper, is known. As described in U.S. Patent Application Publication No. 2003/202051 A1 corresponding to Japanese Patent Application Laid-open No. 2003-326712, the ink-jet head as described above includes those of the type based on the use of the piezoelectric element. In the case of the ink-jet head of the piezoelectric type, when the volume of an ink chamber called “pressure chamber” is varied by an actuator which includes the piezoelectric element, the ink is discharged from a nozzle which is communicated with the pressure chamber. The ink-jet head of the piezoelectric type can use various liquids in addition to the ink as the liquid to be discharged, in which it is possible to realize the precise liquid droplet control and the liquid droplet gradation. The ink-jet head of the piezoelectric type is advantageous in that the durability is excellent.
In recent years, it has been demanded to develop an ink-jet head having a compact size while possessing a large number of nozzles. However, in the case of the ink-jet head of the piezoelectric type, the size of the pressure chamber cannot be decreased to be smaller than a predetermined size when it is intended to secure a certain amount of ink discharge. Therefore, the ink-jet head of the piezoelectric type is not suitable for the realization of the high integration. In other words, it is impossible to arrange the nozzles at a high density, and the head, in which a large number of the nozzles are formed, is consequently large-sized. Further, in the case of the ink-jet head of the piezoelectric type, the flow passage including the pressure chamber is constructed in a complicated manner, in which the production steps tend to be confusing.